Peanut breeders seeking new varieties

Peanut breeders are looking for new varieties that will improve efficiency for Peanut Belt farmers and possibly reduce dependence on foreign oil.

“Genetic improvement of current cultivars is important for the industry,” said John Beasley, University of Georgia Extension agronomist.

“We've had a significant number of new releases in the last few years following more than 30 years of near reliance on Florunner. Today, growers have a lot of options, some with (multiple) pest resistance.”

Current research goals, Beasley said, focus on lowering production costs for farmers who compete in a global marketplace. Breeders also are making a significant push to identify varieties and production techniques that will increase peanut oil production and help boost renewable fuel resources.

Holbrook hopes to find more sources of plant resistance to aflatoxin, tomato spotted wilt virus, leaf spot, drought and root knot nematode. He has a big mineshaft to work.

“We have a germplasm collection of nearly 9,000 accessions,” he said, “collected from around the world. It's a national treasure. But it's an overwhelming job to look for a specific characteristic in that many lines.”

He's dividing to conquer. “We're grouping lines into clusters with similar characteristics. That provides a road map for the entire collection.”

The first division pared the collection down to a cluster of 831 accessions, a good start but still a lot of lines to select from.

“So we took a core from the core and got to 112 lines,” Holbrook said.

From there he'll use molecular markers and chemical attributes to look for resistance and bio-diesel potential.

“We're also doing drought and aflatoxin resistance work. We grow peanuts under moveable shelters. We irrigate as usual for the first 90 days after planting. Then we move the shelters over the plants for the last 40 days to simulate drought stress.”

He's identified a possible breeding line with high yield potential and low aflatoxin contamination under those stressed conditions. “It does not have all the necessary grade characteristics but we hope to identify lines that do.”

Root knot nematode resistance also demands attention. “Some 25 percent of the peanut fields in the Southeast have damaging levels of root knot nematodes,” Holbrook said. (Southwest growers also have rootknot nematode infestations.) “We have no cultivars with high levels of root knot nematode resistance that also has resistance to tomato spotted wilt resistance. Texas has some root knot resistance but not TSWV.”

Marshall Lamb, research leader at the USDA-ARS National Peanut Research Laboratory at Dawson, Ga., said a new breeding program at the lab will focus on production efficiency.

“We'll incorporate the talents of several peanut lab scientists into the effort,” Lamb said. “Diane Rowland, a plant physiologist who works with water efficiency, will play a crucial role. And we're currently advertising for a plant geneticist. We hope to fill that position soon.”

Lamb said variety work is “a long-term process. We're starting from scratch and breeders say they spend 12 to 15 years developing a new variety.”

The peanut lab got a head start, however, from Golden Peanut Company's donation of their AgriTech germplasm. “That was a valuable donation,” Lamb said. He also cited Alabama, Florida and Georgia peanut grower groups as crucial support for the program.

Roy Pittman, USDA-ARS agronomist at Griffin, Ga., is looking at the diversity of South American peanut cultivars, including many wild lines, hoping to identify resistance to tomato spotted wilt virus and other key diseases.

He said York is a later variety with excellent yield and grades with tomato spotted wilt virus, white mold, and leaf spot resistance equal to Georgia Green. “It's almost a complete disease resistance package,” Tillman said and will fit well in a reduced input production system for bio-diesel production.

All three new varieties are high oleic.

Tillman said efforts for the next 10 years will focus on disease and pest resistance with targets including tomato spotted wilt virus, white mold, leaf spot, root knot nematode and CBR. Seed size will be important to cut costs since large seed cost more to plant than small ones.

“Bio-diesel use also will be a factor and late varieties may be good options for fuel use.”

Bill Branch, University of Georgia peanut breeder at Tifton, says two new varieties, GA 011557 and GA 011568, have topped yield and performance tests for three years.

In performance tests, they rank first and second in most trials.

“Both varieties show high yield potential, resistance to tomato spotted wilt virus and good stability across various production environments,” Branch said.

Both will be released this year. Main difference between the two is seed size. “The 57 variety has a higher percentage of jumbos,” he said.